Hello, never posted on this section before so this is all new to me! I'm hoping a good dressmaker will come along and give me a little advice 
I have started making a tunic/dress. It was going really well until a few minutes ago, I managed to cut the material, sew in the darts and zip with no problem.. The size guide said that I needed a size 14-16, whereas I'm usually a 12. I went with it and cut out the pattern to a 14, but it's now too big, even though it's the size I should have due to my measurements!
I'm trying to pin it a little smaller, but I think the problem is that as it was wider than expected, a lot of the dart is in the hem, so it doesn't hang very well (there is a little bit of puckering). I'm not experienced enough to put in extra darts and I'm terrified of messing up what I've already done, but I want it to fit nicely. Help!